Lecture 2 - Chromosomes and Chromatin Flashcards
Chromatin is a complex of _____ and protein.
DNA
Genes in highly ordered (condensed) chromatin cannot be transcribed into _____and are relatively insensitive to DNase.
RNA
The ________ is the basic subunit of chromatin.
Nucleosome
Nucleosomes consist of a core particle, consisting of positively charged histone proteins, and of ______ bp of DNA wrapped twice around the outside of the core particle.
150
________ is condensed, inactive chromatin detectable by microscopy.
is decondensed, active chromatin detectable by microscopy.
Heterochromatin
Euchromatin
Histone acetyl transferases (HATs) add _______ to lysines, reducing the positive charge of the histone proteins and consequently reducing the interaction of the histone proteins with DNA.
Acetyl Groups
Histone deacetyl transferases (HDACs) remove acetyl groups from ______ residues in histone molecules.
Histone methylases add groups to histones.
Lysine
Methyl
The histone post-translational modifications can provide for proteins that facilitate chromatin function.
For example, HP1 facilitates chromatin condensation and .
Binding sites
Gene silencing
ATP-dependent remodeling complexes alter nucleosome structure(s) in a way that facilitates gene expression and requires _______.
ATP
HATs, HDACs, histone methylases, and ATP-dependent chromatin remodeling complexes are brought to specific sequences in the DNA by .
We can call SSDBP a “” when it leads to RNA transcription.
SSDBP
transactivator
In the decondensed form, chromatin provides access to DNA binding proteins via the linker DNA,
destabilized nucleosomes, or ________-free regions.
Histone
The ______________forms by an ordered assembly of components.
Most of the components assemble by contacting other proteins of the PIC, not by contacting .
RNA pol II elongation proceeds by phosphorylation of the RNA pol II carboxy-terminal domain (CTD) by TFIIH.
Pre initiation Complex
DNA
